Dental casting machine



1,490,625. F. C.MONTUORI DENTAL CASTING MACHINE AFiled Dec. 9, 1922 2 Sheets-Sheet l `April 15 1924.

li. I

pril 15 1924. 1,490,625

F. C. MONTUORI DENTAL CASTING MACHINE Filed DeC- 9, 1922 2 Sheets-Sheet 2 Patented pr. 15, 1924.

STATES yPATENT OFFICE'.

DENTAL CASTING MACHINE.

Application led December 9, 1922. Serial No. 605,952.

To all whom t may concern.'

llc it known that l, FELIX C. MoNTUoRI, citizen of the United States, residing at llfashington, in the District of Columbia, have invented certain new and useful Improvements in Dental Casting Machines, of which the following is a specification.

This invention relates `to improvements in mechanism for forming castings particularly inlay castings and cast dentures for restorative work in the oral cavity.

A mechanism of this class generally comprises, in one form or another, 'a flask (containing the investment material with a mold cavity a sprue or gate duct, and a depression or cavity in the top surface thereof for holding the metal toV be melted), a cover or cap adapted to fit tightly upon the top. of the flask, a lever for raising and lowering the cover, an air duct for supplying compressed air to the region in the top of the flask, and a valve in the duct adapted to be opened by the backward movement relatively of the support which carries the cap or cover.

One of the objects of the prese-nt invention is to provide a simpley constructionof parts for a mechanism of this class'by which the valve can be positively moved from, or to. its closing position, independently of the Contact of the cap with the flask, and by which the air under pressure is caused to begin its flow, and its inertia overcome, so that it will be brought to bear upon the molten metal at an instant of time relatively much earlier than is the case with any of the machines within my knowledge.

Fig. 1 is a side elevation of a casting machine embodyingmy improvements.

Fig. Q- is a perspective view of the air valve.

Fig. 3 is a sectional view of the air valve and adjacent parts.

Fig. 4 is a section longitudinal of part` of the lever and handle. n

Fig. 5 is a view partly 1n elevation and Vpartly in section of a modified form of the apparatus.

Fig. 6 is a vertical section of the flask cover and of its vertical moving carriage.

Figs. 7, 8 and 9 show details of the machine in Fig. 5.

Fig. 10 shows in side elevation and section another modification.

Figs. 11 and 1 2 illustrate in details parts of: the mechanism in Fig. 10.

Fig. 13 is a partial section of the base which holds the flask and having a modified yielding flask support.

Fig. 14 is a view, partially in side elevation and partially in vertical section, of another form of dental mold constructed in accordance with the invention and in which a handle controlled poppet valve mechanism is utilized to control the flow of :fluid under pressure to the upper portion of the flask, the flask cover being shown in its raised position and with the valve mechanism closed.

Fig. 15 is a view similar to Fig. 14, but showing the flask cover in its lowered position and with the valve mechanism opened to admit fluid under pressure to the upper portion of the flask.

Fig. 16 is an enlarged vertical sectional view through the supporting member or carrier, the flask cover being shown in side elevation.

Fig. 17 is an enlarged fragmentary vertical sectional view through the upper portion of the pedestal or upright and showing the poppet valve mechanism in elevation.

Considering the mechanism illustrated in Figs. 1. to 4; a support or frame-like device is indicated as an entirety by 10. It comprises an upright 11, a base 12, a horizontal arm 12'1 and an elongated vertical guide tube 13 preferably all cast integral.

The base part 12 is formed with a cavity or aperture at 14 adapted to permit the seating kof a flask such as indicated at 15 containing a mold of the shape desired. The flask may be of any suitable sort; as shown it is adapted to receive the plaster or mold material. 16 indicates the mold cavity, 17 the sprue passage and 18 the usual cavity formed in the upper surface part of the mold material to hold the metal which is to be melted and forced down into the mold cavity 16. The flask may be of either of several sizes such as indicated at 15, 15a, 15b, that one being used which corresponds with the size of the casting to be made. 19 indicates the cover or cap which fits upon the top of the flask. This also may be of any suitable sort. As shown in Fig. 3 it is adapted to be moved vertically and is formed with a toppart (see Fig. 3),

. an outer flange 21, and an inner flange 21a with a packing 21b 4for effecting a tight fit with the top of the flask,

The cap 19 is attached to a vertically movable carrier or support 23 through which there is an air passage 24 extending from the bottom to the top. As shown, the carrier or support 23 is tubular and somewhat elongated.

rlhe carri-er is arranged to reciprocate in the tube 13 and has at its upper end a plug or closingdevice 28 adapted to serve as a stop at 2T for the downward movement of the carrier and also adapted to receive the mechanism which introduces the air. This mechanism is indicated, as an entirety by 44 and comprises an inlet duct at 45, a` gauge liti, and a control mechanism at fl'i'. The stem #i8 is secured in the closing device 28 at the upper end of the carrier 23. 35 indicates a. lever which is pivotally mounted at 40 on the upright ll and is provided with a handle 36. 3"? (Figs. 2 and 3) is a valve to controlV the passage of the air to the cover and liaslr. The cover is. formed with or secured to short tube or boss 38 which is tightly litted to the lower end of the carrier 93. In this boss 3S there is an air duct 39 below the valve and air duct ll above it. The valve has an air passage 37a and is titted in a seat formed in the boss The lever 35 is forked, having) two leg elements 35a. ln the leg-parts are formed longitudinal slots 413, the slotted parts of the legs lying opposite to the ends of the `valve. The valve is caused to rock from the closed position to the openposition and back by attachments thereon en gagging; with the edges ot' the slots. The attachments shown are flat lugs -l9 .vhich niay be lormed integral with or attached to the valve. They4 can be made adjustable, singularly, in relation to the valve. When the cover 19 moves toward its uppermost position the valve is rocked by the lever 35 and the lugs i9 so as to close-V the air duct el, 3L. Shortly after the cover commences to move downward the valve is rocked in the opposite direction by the lever enough to bring the duct 3T to the point where it will let air pass through the cover to the flask. Air commences to pass to the cover while the cover is movingdown and consequently by the time t-he cap reaches the top of the tiaslr and is tightly seated tl'iereon, air under pressure in sufiicient volume is present at the top of the flask ane hea ne upon the nolten metal. This I 'found to a matter of great importance when utilizing metals of' the more refractory sort for the castinos, such metals quickly lose their melting heat. And with any earlier machines in this class within my knowledge, which had the. parts so related, thatfthe air remains out on from thell'asl; until after the cover makes its entire downward movement is beingV pressed tightly against the flask the metal becomes enough eo'oledsotht it cannot be properly forced through the sprue to the mold cavity.

li relatively considerable p riod of time elapses between the instant when the heater is Withdrawn from the flask to the time when the valve is opened and to the instant when the air pressure is felt by the metal.

A valve actuated directly and positively by the manual motor element tor the cap, such as the lever 85, l have found to be much more reliable than those which are actuated by the relatively li achward pressure from and movement ot the cap, directly or indirectly after it has come into contact with the flash,

The valvefand the handle may he made in any suitable way to permit them to assembled or separated. l prefer to foi-in the lever so that the two side parts 35a can be separated as indicated by dotted lines in Fig. et. They can be made of metal sui'iiciently elasticl to permitthe separation ot the'outer ends lar enough to allow the insorting or withdrawal of the valve 3T from its seat and to allow the hinging part-s at Il() to be separated. The nuts, or bolt and nut atlOa, 40h draw the ends of the lever tirmly to position at their outer ends as shown in full lines in Fig. l.

"A valve connected to and actuated by the lever can be made and employed in ways other than that shown in Figs. l to el. One modilication is shown in Figs. to l.V The stand :30 is 'formed with a duct 5l in the upright o; The cover or cap is in this case formed with a -top and llanges and a packing 57. rlhe cover is attached to a carrier 5S arranged to slide vertically in the tubular guide 59`on the upright 52. 6() is a small tube positioned axially within the tubular carrier. The carrier tube is closed at the top by a plug` 6l through which the tube 60 passes.

The cover an upwardly projecting tubular boss 62 which is littedin the lower end of the carrier. The tube 6() vis secured by threaded union in the upper end ot this boss 62. Y

' A chamber 63 isv 'torn'ied in the boss and 64, 64 are two slot-like apertiu'es extending trom the chamber outward.

65 is a pin yevtending` through these slot apertures a nd across the chamhtu'. 66. 66 are apertures in the side walls oll the carrie tube 53 and through these the pin also 11-:tends 67 is the 'spring positioned in the cha Aiber 63. And 68 is a threaded plug;` seated in the lower part of the boss 62 enclosing; the lower end ol' the chamber 63. The spring` 6i' bears Vagainst this' threaded pin and also bears against the underside of the pin, 6.3. The tension of the spring'can be adpisted by the Y threaded plug 68.

69, 69 are air ducts extending from the chamber at 64 below the pipe 60 to the lower end of the boss 63.

70 is a lever with handle 71 and pivoted at 73 to an upright 52. The device at 73 which pivots the lever also serves as a rocking valve to control the air passage. The duct 51 in theA upright extends from the valve chamber at 73 to the upper end ofthe upright. 7a is a duct extending down from the valve chamber and con'imunicating with a short tube 75. To the latter tube a flexible tube 76 is connected, the other end of which is joined to the other end of the tube 60. The valve 73 is formed with a port 77 adapted to put the ducts 51 and 7 4 into communication when the valve is in one position and to cut olf such communication when it is in another. It is adjusted so that the air will begin to pass through it at an instant shortly after the commencement of the downward movement of the cap or cover 53.

In this construction (Figs. 5 to 9, inclusive) the valve 73 is formed with laterally extending hubs with journal parts 78. These are seated in apertures in the forked arms 7 0a of the lever. 79a is a bolt or screw for clamping one ofthe parts 7 0fL of the lever to one of the ournals 7 8 of the valve. 79b vis a bolt on the opposite side of the valve. Between the bolt head and the adjacent part 7 0l of the handle is interposed the spring 8O to provide for adjustment in tension or friction.

The boss 62 on the cover 53 in this coni struction is fitted somewhat loosely in the lower end of the carrier 58 as shown in Fig. 6. This does not interfere with the air tightness of the duct.

In the apparatus in Fig. 5 the air is conducted from a compressor or tank to the inlet duct 51 through devices at 50a for controlling and indicating its pressure similar to those at le in Fig. 1.

Then air is to be admitted to a flask downward movement is imparted to the handle 71 by the lever 70. This moves the cover 53 and shortly after it commences such movement the lever rocks the valve 77 and air is immediately taken from the devices at 50a through the ducts 51, 76 and 60, to the delivery devices at 69. lhen the lever is raised the valve is oppositely rotated and cuts off the air between the ducts 51 and 7&1.

In Figs. 10 to 12 another modified form of mechanism is shown. The stand or frame has the upright 81 with the short vertical duct 82, and base 84 upon which the flash 15b is shown as supported by means of a holder 15C. The cap or cover90 is supported by a vertically moving carrier 88 in the guide 83. At 91 near the lower end of the carrier tube there is an air valve and which is connected to and operated by a lever 92 in the way in which the valve is connected and operated as in the mechanism shown in Fig. 1. The air introducing and controlling mechanism in Fig. 10 is supported upon the upper end of the standard 81 and conimunicatcs with the duct 82. The air from the latter is taken by the connecting tubing T 87 to a nipple or tube at 89 connecting with V-projections 97 adapted to fit in small il-grooves at 98 in the annular plate 94. 99 is a ring plate which engages, at- 100, with the lower ring 96 by means of vshallow V-ribs on plate 99 and V-groove on the upper surface of the ring 96. The V-tongues and grooves at 97 98, and those at 100 are on diameters which are at right angles to each other. Consequently the ring 96 can vibrate for a short distance vertically around a hori- Zontal axis transverse to the base 811 while the ring 99 can vibrate similarly around an axis longitudinal of the base 8e. Upon this top ring 99 the supporter 15c for the flask l 15b is placed. It rests upon a thin perforated plate 104 which fits snugly in the cavity in the plate 84. The holder 15c is centered horizontally by means of a filler ring 103.

It will be understood that a similar filler ring 103 and plate 104C are used when a flash such as that at 15a is employed. `When a large flask such as that at 15 is in the machine it can be placed directly upon the upper ring 99.

In either case there will be possibility for the aslr to yield on any vertical line at its periphery so that it can accommodate itself to the position of the cap or cover. The plate 104 can be supported upon springs, (see `102) Fig. 13. I found that three such springs at 120 apart around the annular plate which surrounds the opening at will be sufficient. As shown in Fig. 13 eachof these springs 102 is seated in a recess 101 formed in the annular plate 911a corresponding` to the annular plate 94 in Fig. 12.

In Figs. 14, 15 and 16 there is illustrated a still further embodiment of the invention l is provided with a vertically extending Ill guide-tube 109 adjacentto its extremity. A substantially tubular carrier or support 110 is slidably mounted within the guide-tube 109 for vertical movement.

The upper end of the carrier 110 is termed with a substantially hemispherical portion 111 which is provided with an aperture 112 extending therethrough. A cylindrical block 113 provided with an axial aperature 114 is secured within the tubular carrier 110, adjacent to the lower extremity thereof, by means of diametrically dis posed screws 115 which project through apertures formed .in the wall of the carrier. A pipe 116 extends axially through the can rier 110 and is slidably mounted adjacent to its upper and lower ends respectively, in

the aperture 112 in the` hemispherical portion 111 and in the aperture 114 in the block 113.

The lower extremity or" the pipe 110 is suitably secured to an upwardly extending boss 117 of a cover or cap member' 118. f he boss 117 is preferably termed integrally with the cap 118 and is centrally disposed with respect thereto and is adapted to eirtend within and slidably engage the lower end of the carrier 110. The lower face of the bloclr 113 is recessed as indicated at 119 and forms a seat for a coil spring 120 which encircles the pipe 116 between the bloclr 113 and the upper :tace ot the boss 117. The spring 120 provides for a certain degree of resiliency between the cap 118 and the carrier 110 when the former is brought into operative engagement with the upper portion of the flask 106. A collar 120 is adjustably secured to the upper port-ion ot the pipe 112 and not only prevents the pipe from becoming displaced but limits the amount of relative movement between the cover 118 and the carrier 110. The carrier 110 and its directly associated parts are reciprocated by means ot a lever indicated as a whole at 121. rllhis lever comp 1ises a handle portion 122 `from which diverge a pair oi substantially parallel legV portions 123 which are pivotally connected to each side of the upright 107 as at 124. VThe leg portions 123 of the lever 121 are each provided with a slot 125 through which the screws 115 are adapted to project 'for slidable engagement therewith when the carrier 110 and cap member 118 are raised and lowered by means of the handle 122. The pivotal connection 124 between the leg portions 123 and the upright or pedestal 107 preinerably comprises a rotatable pivot member 126l which extends transversely through the.

upright 107 and which is suitably fixed to the extremities of the leg portions 123 to move therewith.

The upper portion ci the upright 107 is providedwith a chamber 127 which is communicably connected with the upper poru needeae tion of the pipe 11G byV means ot the flexible tube The chamber 127 is divided into upper and' lower compartments 129 and 130 by means oi a horizontally disposed wall or partition 131. The upper compartment 129 is normally closed by means of a screw plug 132 which is provided with a centrally disposed aperture 133. A nipple i threaded into this aperture and carries an air control mechanism 135 which is connected to a suitable source of compressed air not shown) by means ot a pipe or tube A pressure gauge 137 is suitably connected to the control mechanism 135 by means of which the pressure in the circuit may be accurately ascertained.

rl`he partition 131 is provided with a centrally disposed aperture 138 which may be opened and closed to establish communication between the source'of supplyY of compressed air and the upper portion of the iflaslr 106 by mean-s ot a poppet valve 139. rlhis poppet valve 139 is normally maintained in closed position by means ci a coil spring 140 which is interposed between the upj er portion thereof and the screw plug 132. rlhe poppet valve 139 is provided with a depending rod or stem 141 which eX- tends downwardly through the aperture 138, chamber 1307 through a centrally disposed bore termed in t-he upright 107 and terminates at a. point contiguous to the rotatable pivot member The pivot member 126, adjacent to the point oit' contact with the lower extremity of the rod 141, is provided with cam surface 142 which is adapted to be brought to bear against the lower extremity of the rod 1417 when the lever 121 is actuated to lower the cover and raises the poppet valve 139 carried thereby against action of the spring 140 to admit air to the upper portion et the flask 106.

'lhe length of the rod 141 may be adjusted to compensate for wear to the lower extremity thereof and the cam surface 142 as well as to the valve member 139 and its cooperating` valve seat by any suitable means such as the screw and lool; nut construction illustrated as a whole at 143 (F ig. 17).

rlhe rotatable member 126 is adjustable circum'terentially with respect to the operating handle 121 in order to accurately position the c surface 142 with respectto the lower est ty of the rod 141 so that the openi g he valve will be timed properly with the lowering oli the cover 118, as has been emphasized in connection with the other forms of the invention. rl`his can be done by .raising or lowering the screw in Fig. 17. ln Fig. 7 by loosening the screw 79a and slightly turning the valve 7 3 relative to the lever 70,`and then tightening said screw again.

W hat l claim is:

1. rl`he method of making dental castings iso with the aid of the pressure ci air the like on the molten metal in a closed mold so that the metal is torced into all parts of the mold, which consists in causing the inertia of the air to be overcome and its Llow to the mold to begin bet'ore the mold is entirely Closed to confine the air.

2. ln a metal casting machine oit class described, the combination oi". a iaslr containing a mold cavity, a movable cover therefor adapted to close the flash against any substantial escape of air, means for closing and opening said cover relative to the flask, means for supplying duid pressure within the laslr when it is closed and devices cooperating; with the coveractuating` means to cause the movementot the compressed air to the ilaslr to begin before said cover has closed the tlaslr.

3. ln a casting; machine of the class described the combination oit the vertically movable dash-cover, the stationary upright adapted to support the cover, the duct in the upright adapted to be put into communication with the space below the cover, the vertically vibratable lever, the valwe mounted in the upright for said duct connected adjustably to the lever and ed to be moved thereby to its open position while the cover is moving downward.

d. ln a casting machine of the class described, the combination oli the cover, the carrier for the cover movable vertically therewith and also movable vertically independently thereof, the stationary upright supporting the carrier and havingan air duct, the valve in the upright arranged to control said duct and the lever connected adjustably to the valve and arranged to open it while the cover is moving downward.

5. ln a metal casting machine ot the class described, the combination ot a llaslr com taining a mold cavity and narrow spree leading thereto, a movable cover therefor adapted to close the flaslr against any substantial escape of air, means for closing and opening said cover relative to the means for supplying luid pressure within the flask when it is closed and devices cooperating with the co-verectuating; means to cause the movement ot the compressed air to the flask to begin before said cover has closed the flask.

6. ln a metal casting machine of the class described, the combination of a flask containing a mold cavity, a movable cover! therefor adapted to close the dash against any substantial escape of air, means for closing and openingr said cover relative to the flask, means for supplying iluid pressure within the laslr when it is closed, devices cooperating with the cover-actuating means to cause the movement of the compressed air to the llask to begin before said cover has JJ the closed the flask, and adjusting means to regulate the time ot beginning ot' said movement et said air relative to the time of closing` of said cover.

7. ln a metal casting machine of the class described, the combination of a ilasl containing mold cavity, a movable cover therefor adapted to close the tlaslr against any substantial escape of air, a lever for closing and opening` said cover relative to the ilaslr; means for supplying lluid pressure within the ilaslr when it is closed, a valve actuated by said lever to cause the movement of the compressed air to the laslr to begin before said cover has closed the flash, and means for adjusting` said valve to regulate the time of beginning of said movement of said air relative to the time oil closing of ysaid cover.

8. ln a casting machine of the class described, the combination of a base portion adapted to support a flask, an upright carried by said base portieri and having a plurality of compartments formed therein, a carrier slidably mounted on said upright, a cover carried by said carrier tor cooperation with said tlasl-f., means for communicably connecting one or" said compartments with said cover, means for communicably connecting the other of said compartments with a source of fluid under pressure, a poppet valve mechanism i'or establishing and interruptingV communication between said compartments, a lever pivotally connected to said upright tor raising and lowering said carrier and said cover and means movable with said lever for opening said valve before said cover is closed on said flash.

9. ln a metal casting machine of the class described, the combination ot a llaslr support the vertically movable flask cover, the stationary1 support for the cover, the air duct communicating with the space below the cover, the lever, and the poppet valve mechanism in the stationary support arranged to be moved from its closed to its open position by the lever before the cover is closed on said {ia-slr.

l0. A dental molding machine comprising a base adapted to support a flask, an upripglr carried by said base, a cover for said Hash' movably mounted on said upright, aipes for conducting fluid under pressure through said cover to the upper portion of said flask, a handle for raising and lowering said cover with respect to said llaslr, a valve mechanism operatively connected to said handle and means for opening the valve betere the cover is closed on the flask, whereby the inertia of the iluidin said pipes will be overcome and said fluid will have commenced to flow by the time that said cover engages said flask upon its downward movement.

ln testimony whereof l alle: my signature.

FELIX C. MONTUORL 

